The goal of this project is to make sufficient numbers of specific pathogen-free rhesus monkeys available for AIDS research. To accomplish this, breeding colonies are established and monitored serologically and by viral culture for the presence of retroviruses and herpes B virus which are known to have deleterious effects in animal models for AIDS. Only animals negative for these agents are kept for breeders. At present, the colony of rhesus monkeys has a proven history of being specific pathogen-free, as well as being tuberculin test negative. This is a closed colony, so the SPF status is unlikely to change. The reproductive performance to date is also very good. Since all animals are housed in compatible groups, the incidence of abnormal behavior is almost nil In the original request, it was indicated that a target population of 40 females and 8 males would be sought. At this time, it is felt that the group could be expanded by another 12 to 15 females and 3 males to further increase production. To do this, an existing room in the Michigan Department of Public Health animal facility can be fitted with three additional gang cages, and a curb and gutter to adequately house these animals who will be derived from offspring of the existing group. Because of the tightly controlled conditions under which the monkeys are kept, they can be kept totally naive in terms of receiving any medicine or biologic product other than ketamine and intradermal tuberculin.